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authorVivek Goyal <vgoyal@redhat.com>2011-10-25 15:48:12 +0200
committerJens Axboe <axboe@kernel.dk>2011-10-25 15:48:12 +0200
commita38eb630fa224d6fba8c14a4063174bc5e0f63bb (patch)
treeb86cb5b0aaa4b6d45d798b5155ed2089177f8206 /block
parente060f00beee23568fe2c4faf1e88ff22edefd7b2 (diff)
downloadlinux-a38eb630fa224d6fba8c14a4063174bc5e0f63bb.tar.gz
blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
blkcg->policy_list is protected by blkcg->lock. Its not rcu protected list. So even for readers, they need to take blkcg->lock. There are few functions which were reading the list without taking lock. Fix it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c54
1 files changed, 40 insertions, 14 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 61553670735..8f630cec906 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -869,60 +869,86 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
dev_t dev)
{
struct blkio_policy_node *pn;
+ unsigned long flags;
+ unsigned int weight;
+
+ spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
BLKIO_PROP_weight_device);
if (pn)
- return pn->val.weight;
+ weight = pn->val.weight;
else
- return blkcg->weight;
+ weight = blkcg->weight;
+
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ return weight;
}
EXPORT_SYMBOL_GPL(blkcg_get_weight);
uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
{
struct blkio_policy_node *pn;
+ unsigned long flags;
+ uint64_t bps = -1;
+ spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_read_bps_device);
if (pn)
- return pn->val.bps;
- else
- return -1;
+ bps = pn->val.bps;
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ return bps;
}
uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
{
struct blkio_policy_node *pn;
+ unsigned long flags;
+ uint64_t bps = -1;
+
+ spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_write_bps_device);
if (pn)
- return pn->val.bps;
- else
- return -1;
+ bps = pn->val.bps;
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ return bps;
}
unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
{
struct blkio_policy_node *pn;
+ unsigned long flags;
+ unsigned int iops = -1;
+ spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_read_iops_device);
if (pn)
- return pn->val.iops;
- else
- return -1;
+ iops = pn->val.iops;
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ return iops;
}
unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
{
struct blkio_policy_node *pn;
+ unsigned long flags;
+ unsigned int iops = -1;
+
+ spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_write_iops_device);
if (pn)
- return pn->val.iops;
- else
- return -1;
+ iops = pn->val.iops;
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ return iops;
}
/* Checks whether user asked for deleting a policy rule */